The Pinwheel Galaxy

This fantastic image of the Pinwheel Galaxy was obtained using the Wide Field Camera on the Isaac Newton Telescope. It´s a three-colour composite made from data collected through the filters Sloan g´, r´+Hα
and i´.
Credit: R. Barrena and D. López (IAC). [ JPEG | TIFF | PDF (with text) ]

The Pinwheel Galaxy, also known as Messier 101 or NGC 5457, is a grand-design spiral galaxy located at a distance of about 27 million light-years from Earth.
It is nearly twice the size of our Milky Way.

M101 is usually referred as a classical example of an spiral galaxy. The observed deviation from symmetry is associated with a recent galaxy encounter, that triggered strong star formation visible now as
bright HII regions, or the red spots in the image shown above.

This image was obtained and processed by members of the IAC astrophotography group (A. Oscoz, D. López, P. Rodríguez-Gil and L. Chinarro).